Swivel chair



Dec. 8, 1959 M. M. Bo'nV'EMlLLER ETAL 2,916,084

SWIVEL CHAIR Filed May 28, 1956 United States Patent O Bertha, Minn.,assignors to Homecrest Company, Wadena, Minn., a corporation ofMinnesota Application May 2B, 1956, Serial No. 587,539

7 Claims. (Cl. 15S-'95) The present invention is concerned with a swivelchair, and more particularly with one which provides for a rockingaction. v

The present invention is particularly concerned with a swivel chairwhich also rocks, and which is of an eX- tremely simple construction.

An object of the present invention is to provide a chair of theswivelling and rocking type which, except for the upholstery, can beformed entirely of metal parts.

A further object of the present invention is to provide 'a chair of thist'ype in which all of the parts, except for the upholstery, can be madeby forming or stamping operations.

A still further object of the invention is to provide a chair asdescribed above in which simple means are provided for adjusting theforce required to rock the chair.

A further object of the invention is to provide such an arrangement inwhich the chair seat can be readily assembled and disassembled from thebase structure so as to facilitate shipping.

A further object of the present invention is to provide in such a chair,a'n extremely simple stop construction to limit the rearward tilting ofthe chair.

A still further object of the invention is to provide an extremelysimple base construction for such a chair.

B'roadly, we accomplish the above objects by securing coil springsdirectly t'o the upper swivel plate of a swivel unit,` the chair 'seatbeing adjustably and removably secured to the upper ends of these coilsprings.

Further objects of the invention and the manner in which the recitedobjects are accomplished will be apparent from the accompanyingspecification, claims, and drawing, in the latter of which:

Figure 1 is a perspective view of our improved chair with the upholsteryshown in dotted lines;

Figure 2 is a top plan view of the base construction of our chair;

Figure 3 is a si'de elevational view of our chair with the base rotated45 'from the position of Figures 1 and 2 and with portions broken awayor shown in section;

Figure 4 is a bottom pl'an view of the base construction of our chair;

Figure S 'is an elevational view of the stopv means in our chair tolimit the rocking movement.

Figure 6 is a detail view showing how the upholstery pa'd is retained inposition on the vframe of the chair seat.

Referring now to rthe drawing, it will be noted that the chair consistsof a main chair seat 10 secured to coil springs 11 and 12, which are`rigidly secured to a swivel unit 13V supported by a plurality of legs14, 15, 16, and 17. The swivel unit 13 comprises a pair of stamped sheetmetal plates 19 and 20, which are formed to provide a bearing racetherebetween containing bearings 21. The two plates 19 and 2t), and thebearings 21 are held in assembled relation by a central pin 22, which isprovided with a head on one side and is peened over on the other side.

A pair of one-and-a-half turn coil springs 11 and 12 ICC are secured tothe upper plate 19, as best shown in Figures 2 and 3. Coil spring 11 isprovided with an elongated lower end 25 corresponding in curvature tothe periphery of the upper swivel plate 19. Coil spring 12 has a similarcurved lower end 26, curved in the reverse manner. The lower ends 25 and26 snugly engage a flange portion 28 of the upper swivel plate 19 andare welded thereto at a plurality of points, as indicated by welds 30,31, 32, and 33. As best indicated in Figure 3, the upper plate 19extends upwardly from the flange portion 28 to provide a vertical wall34 against which the coil spring engages and to which it may be welded.The fact that the flange portion 28 is depressed below the rest of theplate 19 not only strengthens the swivel unit but aids in carrying awaythe heat of the welding operation from the springs.

The upper ends 35 and 36 of the coil springs 11 and 12, respectively,likewise are elongated and extend horizontally. These elongated andhorizontalend's 35 and 36 are provided for supporting the chair seatportion of the chair as will be described shortly.

The four legs 14, 1S, 16, and 17 are of hollow metal tubing and aresecured to the lower swivel plate 2a, as best shown in Figures 3 and 4.Each of these legs is curved and has secured to its lower end aconventional glide 39, or so'me other suitable device for minimizing thetendency of the legs to press into the oor surface. The 'upper end ofeach leg is bent at right angles and then flattened. Referring to leg16, for example, the leg is curved until it extends horizontally. Thishorizontal portion is Welded to a flange 42 of the lower plate 2li,which flange corresponds to and mates with the ange 28 of the upperplate 19. The innermost portion of leg 16 is then bent vertically 'at 44and horizontally at 45, the horizontal portion 45 being flattened andwelded to the underside of the lower swivel plate 20. Each of the legs14, 15, 16, and 17 is similarly fastened at two points to the lowerswivel plate. It will be noted that as downward pressure is applied tothe swivel unit, pressure is applied through flange 42 to the horizontalportion of the leg. The leg is prevented, however, from rocking aboutllange 42 because of the end 45 thereof being welded to the lower plate20. The construction provided is a very rigid one. To further increasethe rigidity of this base portion, there is a circular ring 49 whichextends within the legs 14, 15', 16, and 17, and is welded to each ofthese legs. This ring serves to further prevent spreading apart of thelegs.

Referring now to the chair seat portion 1t) of our improved chair, itwill be noted that this portion is formed of a plurality of rods whichextend at right angles to each other and are `welded together and to anouter rod 5'2, which forms an outer rim for the chair seat. Secured to,and forming part of the chair seat con-struction, are a pair of rods 53and 54 which extend horizontally and then nearly vertically to form armsof the chair. Brackets 55 are provided on these arms for securing pads56 shown in dotted lines. Also shown in dotted lines, in Figure l, is apad 57, designed to cover the frame of the chair seat and to cushion thesame.

The pad 57, as partially shown in Figure '6, is retained in place byhaving a plurality of button holes 51 in the back thereof (only one ofwhich is shown), which engage -over the lends of rods 58 of the chairseat construction. In this manner, the pad 57 can be quickly removed bymerely slipping the button holes 51 in the back thereof off the ends ofrods 53.

Secured to opposite ends of cross rods 59 and 60 of the chair seat are apair of main supporting bars 61, only one of which is visible in itsentirety in the drawing and more particularly in Figures 1 and 3.Secured to each of these bars 61 is a sleeve 62, as by welding. The

sleeve 62 has an internal diameter substantially the same as theexternal diameter of the upper horizontal ends 35 and 36 of the coilsprings`11 and 12, andV is designed to slide over these ends. Thesleeves 62 are spaced apart a distance similar to the spacing betweenrods 35 and 36 so that the chair seat construction can be secured to theends 35 and 36 by sliding the sleeves 62 over these ends. The ends 35and 36 are provided with set screws 63 which are inserted after thesleeves 62 have been slid on to the ends 35 and 36, and these set screws63 prevent accidental removal of the chair seat from the base. Thesleeves 62 are provided with further set screws 65 which extend throughthe sleeve and engage the springs upon being tightened. As evident fromFigure 3, the sleeves 62 can be adjusted longitudinally to shift theposition of the chair seat with respect to the center of springs 11 and12. This provides an adjustment of the rocking action. The farther outthe sleeves 62 are, the greater is the leverage exerted by the occupantof the chair and the easier it is for the chair to be rocked. As thesleeves 62 are adjusted inwardly towards a point directly above thecenter of the springs, more force is required to rock the chair and theeffect is that of a stiffer spring. The set screws 65 provide forlocking the sleeves 62 in the position in which the chair seat is in thebest position for the comfort of the user.

It is to be noted, looking at Figure 3, that the center of springs 11and 112 is slightly forward of the center of the base construction. Thisprovides for the center of gravity of the body of the occupant beingmore nearly over the center of the swivel. This, in turn, results insmoother swivelling action.

It is to be further noted that the chair seat is supported on the basestructure by two rods 61, which are fastened to the chair seat only attheir outer ends. These rods, while sufliciently rigid to preventbending thereof. during normal occupancy of the chair, can be bent foradjustment purposes at the factory to adjust the angle with respect tothe horizontal at which the chair seat is normally disposed.

The rocking motion of the chair is limited by a U- shaped bar 68 (bestshown in Figures 3 and 5), which has npturned ends welded to sleeves 62.As will be apparent from Figure 3, the stop bar 68 serves to limit therocking motion of the chair because of the stop bar engaging the upperswivel plate 19. The bar 68 also helps to maintain the correct spacingbetween sleeves 62.

It Will be readily apparent that the present chair provides both aswivelling and rocking action. The rocking action is due to the flexingof the coil springs 11 and 12, while the swivelling action is due to theaction of swivel unit 13. It will be further seen that the constructionof our chair is extremely simple and can be made of parts that arestamped or formed, no cast parts being required.

While we have shown a specific embodiment of our chair, it is to beunderstood that this is for purposes of illustration only and that theinvention is to be limited solely by the scope of the following claims.

We claim as our invention:

l. In a swivel and rocking chair, a swivel unit comprising upper andlower relatively rotatable swivel members, base means secured to saidlower swivel member to support the chair, a pair of parallel coilsprings having upper and lower horizontally extending end portions, saidlower end portions being rigidly secured to said upper swivel member, achair seat, sleeves secured to the under portion of said chair seat,said sleeves having an internal size and shape substantially the same asthe external size and shape of the upper horizontally extending endportions of said springs and spaced apart the same distance as saidupper coil end portions so that said coil end portions slidably receivesaid sleeves, means for securing said sleeves and chair seat in aselected position with respect to said coil springs, and a bar whoseends are secured to said sleeves to maintain the same properly spacedand whose intermediate portion extends downwardly to engage said upperswivel member when said chair seat is rocked backwards a predeterminedamount.

2. ln a swivel chair; a swivel unit comprising an upper metallic swivelplate having a raised center portion, a lower metallic swivel platehaving a corresponding raised center portion, bearings interposedbetween said swivel plates, and means for rotatably interconnecting theswivel plates; a chair seat; means securing said chair seat to andsupporting it on said upper swivel plate; and base means secured to saidlower swivel plate to support said chair, said base means comprising aplurality of radially extending tubular legs having their inner endsflattened and fastened to the under side of the raised center portion ofsaid lower swivel plate and having intermediate tubular portions thereofyfastened to the under side of the outer portion of said lower swivelplate.

3. In a swivel chair; a swivel unit comprising an upper metallic swivelplate having a rim and a raised center portion, a lower metallic swivelplate having a corresponding rim and raised center portion, bearingsinterposed between said swivel plates, and means for rotatablyinterconnecting the swivel plates; a chair seat; means securing saidchair seat to and supporting it on said upper swivel plate; and basemeans secured to said lower swivel plate to support said chair, saidbase means cornprising a plurality of radially extending legs havingtheir inner ends fastened to the under side of the raised center portionof said lower swivel plate, and having intermediate portions thereoffastened to the under side of said rim.

4. In a swivel and rocking chair; a swivel unit comprising an uppermetallic swivel plate, a lower metallic swivel plate, each of saidswivel plates having an annular rim, a raised circular center portion,and a shoulder between said rim and said center portion, bearingsinterposed between said center portions of said plates, and means forrotatably interconnecting said swivel plates; a pair of parallel coilsprings having upper and lower end portions, said lower end portionsbeing elongated and extending horizontally around the rim of said upperswivel plate adjacent the shoulder thereof and welded to the rim, saidshoulder and the heat radiating characteristics of said rim serving toretard the transmission of the heat of welding to the center portion andthe bearings; a chair seat; means securing said chair seat to the upperend portions of said coil springs; and base means secured to said lowerswivel plate to support said chair.

5. In a swivel and rocking chair; a swivel unit comprising an uppermetallic swivel plate, a lower metallic swivel plate, bearingsinterposed between said swivel plates, and means for rotatablyinterconnecting the swivel plates; a pair of parallel vertical coilsprings, each having at least one and a half turn coils and each havingupper and lower end portions, said lower end portions being elongatedand curved and extending horizontally along and welded to said upperswivel plate to hold said springs rigidly in vertical position, with themajor extent of said lower end portions in direct engagement with saidswivel plate and with the centers of said coils on a line which is notsubstantially displaced horizontally from the center of said swivelunits; a chair seat; means securing said chair seat to the upper endportions of said coil springs; and base means secured to said lowerswivel plate to support said chair.

6. In a swivel and rocking chair; a swivel unit comprising an uppermetallic swivel plate, a lower metallic swivel plate, each of saidswivel plates having a rim and a center portion in a plane displacedfrom the plane of said rim, bearings interposed between the centerportions of said swivel plates, and means for rotatably interconnectingthe swivel plates; a pair of parallel coil springs having upper andlower end portions, said lower end portions being elongated andextending horizontally along and welded to the rim of said upper swivelplate, the displacement of said rim from said center portion serving toretard the transmission of the heat of welding to the center portion andbearings; a chair seat; means securing said chair seat to the upper endportions of said coil springs; and base means secured to said lowerswivel plate to support said chair.

7. In a swivel and rocking chair; a swivel unit comprising an uppermetallic swivel plate, a lower metallic swivel plate, each of saidswivel plates having a rim and a center portion in a plane displacedfrom the plane of said rim, bearings interposed between the centerportions of said swivel plates, and means for rotatably interconnectingthe swivel plates; a pair of parallel coil springs having upper andlower horizontally extending end portions, said lower end portions beingelongated and extending horizontally along and welded to the rim of saidupper swivel platethe displacement of said rim from said center portionserving to retard the transmission of the heat of welding to the centralportions and bearings; a chair seat; sleeves secured to the underportion of said chair seat, said sleeves having an internal size andshape substantially the same as the external size and shape of the upperhorizontally extending end portions of said springs and spaced apart thesame distance as said upper coil end portions so that said coil endportions slidably receive said sleeves; means for securing said sleevesand chair seat in a selected position with respect to said coil springs;and base means secured to said lower swivel plate to support said chair.

References Cited in the le of this patent UNITED STATES PATENTS 499,718Cutler June 20, 1893 1,809,453 Schram June 9, 1931 2,528,949- EngstromNov. 7, 1950 2,598,788 Hamilton June 3, 1952 2,625,983 Slyter Jan. 20,1953 2,671,631 Fox Mar. 9, 1954 FOREIGN PATENTS 164,140 Switzerland Dec.1, 1933

